Hereditary Angioedema (HAE) is a rare genetic disorder characterized by recurrent episodes of swelling in various parts of the body. It is caused by a deficiency or dysfunction of a protein called C1 esterase inhibitor (C1-INH), which plays a crucial role in regulating the immune system and preventing excessive inflammation.
The history of Hereditary Angioedema dates back to the early 19th century. The first documented case of HAE was reported in 1888 by Sir William Osler, a renowned Canadian physician. He described a patient with recurrent episodes of swelling and abdominal pain, which he referred to as "hereditary angioneurotic edema."
Over the years, several other cases were reported, and researchers began to recognize the hereditary nature of the condition. In the 1960s, it was discovered that HAE is inherited in an autosomal dominant manner, meaning that an affected individual has a 50% chance of passing the condition on to their children.
In the 1970s, the underlying cause of HAE was identified. Scientists found that individuals with HAE had low levels of C1-INH or a dysfunctional form of the protein. This breakthrough led to a better understanding of the disease and paved the way for diagnostic tests.
Throughout the 20th century, treatment options for HAE were limited and often ineffective. Patients relied on supportive care, such as pain management and fluid replacement, to alleviate symptoms during attacks. However, significant advancements in HAE treatment occurred in the late 1990s and early 2000s.
In 1999, a plasma-derived C1-INH concentrate became available for HAE treatment. This concentrate, derived from human blood, provided a replacement for the deficient or dysfunctional C1-INH protein. It proved to be effective in reducing the severity and duration of HAE attacks.
Another milestone in HAE treatment came in 2008 with the approval of the first C1-INH replacement therapy derived from recombinant DNA technology. This therapy offered an alternative to plasma-derived concentrates and provided a more sustainable and reliable source of C1-INH.
Since then, additional medications have been developed to prevent and manage HAE attacks. These include bradykinin receptor antagonists, which block the effects of bradykinin, a key mediator of swelling in HAE.
Today, individuals with HAE have access to a range of treatment options that can significantly improve their quality of life. Ongoing research continues to deepen our understanding of the disease and may lead to further advancements in diagnosis, prevention, and treatment.